Hi Shahid,
I don't see anything obvious.
Did you see any messages when you activated?
I assume you followed all the instructions in the SAP HANA Academy videos...?
SAP River: Getting Started | SAP HANA
SAP River: Enabling the Development Environment | SAP HANA
SAP River: Creating the Development Environment | SAP HANA
SAP River: Hello World | SAP HANA
What happens if you remove the "Plant" entity then re-activate - effectively the same RDL as the HelloWorld app in the above videos?
You might also try restarting the HANA server and also HANA Studio - could be a caching issue if you've previously activated the RDL with differeny syntax?
Cheers,
Philip